1. Field of the Invention
The present application relates to a driver circuit implemented within an transmitter optical module, in particular, the application relates to a driver circuit powered by two power supplies which are sequentially activated.
2. Related Background Art
A driver circuit implemented within a transmitter optical module has been requested to output signals with large amplitude for driving an optical device. A United States Patent Application US20120113999A has disclosed a driver circuit able to output a signal with enough amplitude. In order to obtain the output with enough amplitude, an output stage of the driver circuit is preferably powered by a power supply with a higher voltage. However, when the higher power supply is a kind of boosting circuit powered by a lower power supply, instable conditions between the power supplies may occur, which possibly degrades active devices and sometimes damages them.